How long have you had it?Around 4/5 years, I raised her from a hatchling

What is the water temperature?My thermometers are a little iffy, but the Jager heater should be keeping it at around 79 degrees.

Did you use a thermometer?Yeah, but I don't trust it.

Are you using a water heater?Yes.

How much water is in there?55 gallons, shared with another YBS female

Are you using a water conditioner?Yes

Are you using any filtration?Yes, a fairly new Sunsun canister filter.

What is the basking temperature?Unsure.

Is there a basking light?Yes.

Is there a basking platform that is easy to climb on?Yes

What kind is it or what is it made out of?Mega Ray 100 watt.

Is there a UVB light?Yes, it is a new bulb.

What have you been trying to feed it?Mordin's diet usually consists of Baby Romaine leaves on a daily basis and reptomin pellets every other day, but I have been away for the past week and she has only been getting the pellets.

When was the last time your turtle ate?I watched Mordin eat on Thursday via webcam. She seemed to have an ordinary appetite then.

How big is the tank/pond/enclosure?55 gallons, shared with another YBS, they are separated by a homemade barrier. I realize this is too small and I'm planning an upgrade.

Is the tank near a window?No. It is by a mirror though.

Is the tank in a room with a lot of activity?Not usually. Today my wife and I arrived home for the first time in a week, so there was more activity than usual.

Have you read the Basic Care section?Yes.

Have you searched the forums for similar situations?Yes.

Is there any other unusual activity/symptoms?

Today Mordin refused all food and has barely moved for most of the day (she is usually very active).

I tried offering her leaves and a strawberry (something she doesn't get often and usually goes crazy for), but she wasn't having it.

She is keeping her eyes closed more than usual - I'm having a hard time telling if they're a little swollen or not. After we returned home, she shot down from the basking dock and hasn't basked since. Usually she spends more time up there, especially at night when the light is off - it's where she likes to sleep.

My other YBS, Pinkman, seems to be doing fine, is full of energy and has a big appetite.

It was around this time last year that Mordin started to display eggy behaviour before finally laying eggs for the first time through the early half of this year (she never took to a nesting spot and every time I was convinced she was done, she would drop one or two more in the water).

Could this all be stress, since we just got home, or is it likely to be something more serious?

To be on the cautious side I would separate them so Pinkman does not catch what Mordin has if anything serious , just extra safety. Not enough of any symptoms yet so it could be anything or nothing. Play it safe. With Mordin not feeling well she would be less stressed by not quarantining her , let her stay in regular tank and observe well for any other signs. Since Pinkman is doing well move him /her just in case it's anything contagious , that is until more symptoms if any show up. Did you leave your a/c or heat on while gone...may just be cold she's got ? By me one day hot the next cold with wild temp changes with these fronts.Have a camcorder set it up on Mordin to see what's happening when you not around or at night . Leave regular lights on there day/night cycle , use a lamp for a little indirect light so camcorder can see. May show something ?When was her last Vet visit ? This time last year was dealing with eggs , she could be having a problem this year in that area. Observe well.

I didn't know this when I named them, but Pinkman is a female as well.

They've been separated largely because Mordin kept attacking Pinkman a few years ago. Pinkman would fight back sometimes, but wasn't nearly as brutal.

I haven't been able to separate them yet as I live in a small NYC apartment and don't have anywhere obvious to put Pinkman.

Today I've avoided them and my wife fed them this morning. Here's a weird thing - Mordin has been acting more shy around me than around her (she doesn't usually feed them or interact with them). Mordin will go on basking around her, but if I walk by, Mordin will drop into the water.

Mordin waited for my wife to leave and ate some Baby Romaine. I've been watching them on a camera as Litefoot suggested and Mordin is very active, swimming around, rooting around for crumbs in the sand. Pretty much her usual routine.

Turtles have a good memory. Maybe you woke Mordin up from a good sleep and scared her ? Maybe you moved something she didn't want moved ? Give her some time and observe since you know from video she's ok. Try and place your hand "above" the water , do not move it at all not even your fingers ! Do not go for Mordin and let a trust be reestablished. Something bothered her , give her some time and observe.

Thanks for all the advice. Mordin is doing much better now. She's back to eating normally and has been paddling around with a lot more energy.

It's hard to know what one thing caused the problem or what solved it. I cleaned the filter and tank very thoroughly and addressed the heating situation (it was a couple of degrees too hot).

I really do think it was psychological though, like litefoot said. I'd actually come to think that maybe this was all a reaction to us scaring her when we got home. Mordin has always been a little nervous around people (Pinkman is the opposite and follows me around like a puppy when I pass the tank). There was a time a few years back where she would never eat or bask whilst I was in the room, so I guess she was falling back on old behaviour.

About three days that I know of, after I got back home. I know she was fine about two days before I got back too, but I can't really tell if she ate in those two days. So a minimum of 3, a maximum of 5.